Quote:
Originally Posted by The_Cat
But there may be something else, When stars blow out using a long exposure (1000 Sec) on my refractor scope there is no CA at all. The 85mm shows no CA as long as the stars don't blow out.
Jeremy
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Jeremy I've used my 85mm f/1.2 for astro.
The thing I've found is that it's absolutely critical to get focus spot on else you get this happening.
I see it when using live view and it's very very difficult to get focus spot on.
Also focus can shift throughout the session as temps drop so you need to re-check it now and then.
I also stop it down a couple of stops.